Formation and characterization of strained Si_1-xGe_x films epitaxially grown on Si(100) by low-energy ECR Ar plasma CVD without substrate heating

For quantum-effect nano heterostructures of group IV semiconductors, formation and characterization of Si_1-xGe_x films epitaxially grown on Si(100) by using low-energy electron-cyclotron-resonance (ECR) Ar plasma chemical vapor deposition (CVD) without substrate heating were investigated. Epitaxial Si_0.50Ge_0.50 films with smooth surface can be obtained on Si(100), where the thickness is almost proportional to the deposition time and an incubation period is scarcely observed. For a 12 nm-thick epitaxial Si_0.50Ge_0.50 film on Si(100), its lattice constant in the direction perpendicular to the interface shows that the lattice is highly strained compared to a case of strain-relaxed Si _0.50Ge_0.50. This indicates that our ECR plasma CVD process has a potential to achieve highly strained heterostructures with suppressed strain relaxation and thermal interdiffusion at the heterointerface which are necessary for quantum-effect devices.